My dad scares me a lot mentally?

He does, whether it's when he seems to get angry for no reason, and talks about beating/killing people, rants about his financial problems, and tells me he's leaving. Or sometimes makes me afraid of my own neighbourhood. According to him someone or more likely a group of people ripped our back gate off the hinges and threw it into the yard. Nothing like scaring me in the safety of my own home. I can't say it's surprising, there is this little gang of delinquents that runs around they live right across the street, always ten or so of them. I think I've heard them doing crap before, but this seems to go over the line. I want my dad to quit scaring me, and I don't want to be worried for him about getting jumped by a bunch of punks. Any advice?